# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Tests for ML RNN generator."""

import os
import sys
import tempfile
import unittest

from bot.fuzzers.ml.rnn import constants
from bot.fuzzers.ml.rnn import generator
from system import shell
from tests.test_libs import test_utils

DATA_DIRECTORY = os.path.abspath(
    os.path.join(os.path.dirname(__file__), 'data'))

# Parameters for the demo model.
MODEL_NAME = 'rnn'
MODEL_LAYER_SIZE = 1
MODEL_STATE_SIZE = 2


@test_utils.integration
class MLRnnGeneratorIntegrationTest(unittest.TestCase):
  """ML RNN generator tests."""

  def setUp(self):
    self.model_directory = os.path.join(DATA_DIRECTORY, 'model')
    self.model_path = os.path.join(self.model_directory, MODEL_NAME)

    self.input_directory = os.path.join(DATA_DIRECTORY, 'input')
    self.output_directory = tempfile.mkdtemp()

    self.empty_directory = tempfile.mkdtemp()

  def tearDown(self):
    shell.remove_directory(self.output_directory)
    shell.remove_directory(self.empty_directory)

  def test_generate(self):
    """Test generate specified number of inputs."""
    # Set a large timeout value and a small count value to avoid timeout.
    timeout = 20
    expected_count = 2

    result = generator.run(
        self.input_directory,
        self.output_directory,
        self.model_path,
        timeout,
        generation_count=expected_count,
        hidden_state_size=MODEL_STATE_SIZE,
        hidden_layer_size=MODEL_LAYER_SIZE)

    # Process exits normally and no timeout.
    self.assertEqual(result.return_code, constants.ExitCode.SUCCESS)
    self.assertFalse(result.timed_out)

    actual_count = shell.get_directory_file_count(self.output_directory)
    self.assertEqual(expected_count, actual_count)

  def test_empty_corpus(self):
    """Test generation should abort for empty corpus."""
    # Set a large timeout value and a small count value to avoid timeout.
    timeout = 20
    expected_count = 2

    result = generator.run(
        self.empty_directory,
        self.output_directory,
        self.model_path,
        timeout,
        generation_count=expected_count,
        hidden_state_size=MODEL_STATE_SIZE,
        hidden_layer_size=MODEL_LAYER_SIZE)

    self.assertEqual(result.return_code, constants.ExitCode.CORPUS_TOO_SMALL)
    self.assertFalse(result.timed_out)

    # No new units.
    actual_count = shell.get_directory_file_count(self.output_directory)
    self.assertEqual(actual_count, 0)

  def test_invalid_model(self):
    """Test TensorFlow should throw exception if model does not match."""
    # Set a large timeout value and a small count value to avoid timeout.
    timeout = 20
    expected_count = 2

    # Change model parameters to make demo model invalid.
    invalid_state_size = 8

    result = generator.run(
        self.input_directory,
        self.output_directory,
        self.model_path,
        timeout,
        generation_count=expected_count,
        hidden_state_size=invalid_state_size,
        hidden_layer_size=MODEL_LAYER_SIZE)

    self.assertEqual(result.return_code, constants.ExitCode.TENSORFLOW_ERROR)
    self.assertFalse(result.timed_out)

    # No new units.
    actual_count = shell.get_directory_file_count(self.output_directory)
    self.assertEqual(actual_count, 0)

  @test_utils.slow
  def test_timeout(self):
    """Test timeout case in generation."""
    # Set a small timeout value and a large count value to trigger timeout.
    # Note that timeout cannot be set too small since it takes time to
    # start generator. If this test failed please increase timeout value.
    timeout = 10

    result = generator.run(
        self.input_directory,
        self.output_directory,
        self.model_path,
        timeout,
        generation_count=sys.maxsize,
        hidden_state_size=MODEL_STATE_SIZE,
        hidden_layer_size=MODEL_LAYER_SIZE)

    # Process timed out.
    self.assertNotEqual(result.return_code, constants.ExitCode.SUCCESS)
    self.assertTrue(result.timed_out)

    actual_count = shell.get_directory_file_count(self.output_directory)
    self.assertGreater(actual_count, 0)
